Arthur Moritz Schoenflies

Arthur Moritz Schoenflies (1853 to 1928) was a German mathematician known for applying group theory to crystallography and for his work in topology. He was born in Landsberg an der Warthe, now Gorzów in Poland, and studied at the University of Berlin from 1870 to 1875 under Ernst Kummer and Karl Weierstrass, and was influenced by Felix Klein. He took his doctorate in 1877, taught at a school in Berlin and from 1880 in Colmar. His name is attached to the Schoenflies problem, which asks whether a sphere of one dimension fewer than its Euclidean space must bound a topological ball however it is embedded, a question more subtle than it first appears. He wrote on set theory, kinematics and projective geometry for Klein's Encyclopedia of Mathematical Sciences, and his books include Kristallsysteme und Kristallstruktur (1891) and Theorie der Kristallstruktur (1923). The writer Walter Benjamin was his great-nephew.